We use cookies to improve our service and to tailor our content and advertising to you. More infoClose You can manage your cookie settings via your browser at any time. To learn more about how we use cookies, please see our cookies policyClose

In Novo Nordisk’s internal reports of trials of the diabetes drug repaglinide, Jeppe Schroll finds deaths that were not reported in published trials, potentially underplaying harms in subsequent analyses

Researchers generally do not publish what they planned to report in their protocols,1 and important differences can also exist between internal trial reports and published papers.2 It has been suspected that even deaths are sometimes omitted,3 but there is little direct evidence of this.

In the final stages of conducting a Cochrane review about sulfonylurea treatment for patients with type 2 diabetes,4 I realised that we had included only a few trials that considered outcomes important to patients. This was surprising given that we included several drugs that had been approved in the past 30 years, when clinical evaluation in trials was required. I searched for protocols on http://clinicaltrials.gov, but these trials were conducted before registration was mandatory.

I turned to the website of the US Food and Drug Administration (FDA) to look for reviews that might give clues about unpublished trials. Useful FDA reviews had compared the diabetes drugs repaglinide and nateglinide with sulfonylurea drugs. The sulfonylurea drugs themselves had been approved before the FDA started to publish reviews online. The FDA’s repaglinide review5 …